Testbench builder, system, device and method having agent loopback functionality

ABSTRACT

A testbench for testing a device under test (DUT), wherein the testbench has a verification environment including a reference model, a scoreboard and a customized agent for each interface that the DUT needs to receive input from and/or transmit output on. The testbench system is able to be generated by a testbench builder that automatically creates a scoreboard, a reference model, a dispatcher and generic agents including generic drivers, loopback ports, sequencers and/or generic monitors for each interface and then automatically customize the generic agents based on their corresponding interface such that the agents meet the requirements of the interface for the DUT.

RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119(e) of theco-pending U.S. provisional patent application Ser. No. 62/080,174,filed Nov. 14, 2014, and titled “TESTBENCH BUILDER, SYSTEM, DEVICE ANDMETHOD INCLUDING A GENERIC DRIVER AND TRANSPORTER,” the co-pending U.S.provisional patent application Ser. No. 62/080,158, filed Nov. 14, 2014,and titled “TESTBENCH BUILDER, SYSTEM, DEVICE AND METHOD,” theco-pending U.S. provisional patent application Ser. No. 62/080,214,filed Nov. 14, 2014, and titled “TESTBENCH BUILDER, SYSTEM, DEVICE ANDMETHOD INCLUDING A DISPATCHER,” the co-pending U.S. provisional patentapplication Ser. No. 62/080,194, filed Nov. 14, 2014, and titled“TESTBENCH BUILDER, SYSTEM, DEVICE AND METHOD INCLUDING A GENERICMONITOR AND TRANSPORTER,” and the co-pending U.S. provisional patentapplication Ser. No. 62/080,235, filed Nov. 14, 2014, and titled“TESTBENCH BUILDER, SYSTEM, DEVICE AND METHOD HAVING AGENT LOOPBACKFUNCTIONALITY,” all of which are hereby incorporated by reference.

FIELD OF INVENTION

The present invention relates to testbenches. More particularly, thepresent invention relates to an automatic testbench builder.

BACKGROUND OF THE INVENTION

When developing components for integration into a system, a number oftest procedures are typically performed to ensure that the componentwill operate in the desired manner when integrated into the system. Thedevelopment of a hardware component (also referred to herein as adevice) typically takes place in a number of stages. Firstly, thefunctional operation/behavior of the component is defined, for exampleusing a Register Transfer Language (RTL). Two popular RTLs used are VHDLand Verilog. In addition, prior to performing such RTL coding, abehavioral model may be built using a UML™ (Universal Modeling Language)to validate at a transactional level that the design intent is correct.Once an RTL representation of the hardware component has been developed,this is then synthesised into a sequence of hardware elements using anyof a number of known synthesising tools. The result of the synthesis isa hardware design that can then be used to produce the actual hardwarecomponent, for example using appropriate fabrication of the component onsilicon. It is costly to perform test procedures on the component onceit has been reduced to hardware. Thus, testing of the RTL representationof the component is typically performed to ensure that the actualhardware generated from that RTL representation will operate correctly.

Such testing of the RTL representation typically involves the use of atestbench model providing a test environment for the RTL representationof the component, which is then run on a simulation tool to produce testresults which can be analyzed to determine whether the RTLrepresentation of the component is operating as required. The testbenchcan be formed in a variety of ways. For example, the testbench could beformed to provide a test environment for testing the RTL representationof the component in isolation, which enables direct control of the inputstimuli to the RTL representation of the component. However, thisrequires a particular testbench to be produced for that componentrepresentation. Another approach is to combine that RTL representationof the component to be tested with RTL representations of othercomponents that have already been tested, and with which the componentto be tested will interact. Hence, in this approach, a portion of theoverall system into which the component is intended to be placed isrepresented in RTL, and a testbench is then constructed based on thatRTL representation of the system portion. This avoids the need toproduce a particular testbench specifically for the component to betested, but results in loss of direct control over the input stimuli tothe RTL representation of the particular component to be tested.

BRIEF SUMMARY OF THE INVENTION

Embodiments described herein are directed to a testbench for testing adevice under test (DUT), wherein the testbench has a verificationenvironment including a reference model, a scoreboard, a dispatcher anda customized agent for each interface that the DUT needs to receiveinput from and/or transmit output on. The testbench system is able to begenerated by a testbench builder that automatically creates genericagents including generic drivers, loopback ports, sequencers and/orgeneric monitors for each interface and then automatically customize thegeneric agents based on their corresponding interface such that theagents meet the requirements of the interface for the DUT.

A first aspect is directed to a testbench system stored on anon-transitory computer readable medium for testing operation of adevice under test. The testbench system comprises a plurality of agentseach comprising one or more loopback ports within an verificationenvironment, coupled with the device under test and configured toperform one of outputting testing data to or inputting testing data fromthe device under test such that each of the agents are associated with aportion of the testing data, wherein at least one of the portions isdependent on at least one other of the portions with respect to testingthe device under test, and further wherein one of the loopback ports ofa first agent of the agents that is associated with the at least one ofthe portions is coupled with one of the loopback ports of a second agentof the agents that is associated with the at least one other of theportions for transmitting dependency data between the one of the agentsand the another of the agents. In some embodiments, outputting thetesting data comprises outputting one or more transactions to the deviceunder test and inputting the testing data comprises inputting one ormore device responses to the transactions from the device under test. Insome embodiments, a second of the loopback ports of the first agent iscoupled with a second of the loopback ports of the second agent suchthat there are two connections between the first agent and the secondagent via the loopback ports. In some embodiments, the first agent iscoupled with one or more additional agents of the agents via theloopback ports of the first agent and the additional agents such thatthe first agent is coupled to a plurality of the agents via the loopbackports of the first agent. In some embodiments, each connection couplingtwo of the loopback ports has a traffic direction configured such thatan input lookout port of the ports of the agent associated with thetesting data that is dependent receives the dependency data from anoutput lookout port of the lookout ports of the agent associated withthe testing data that is depended upon. In some embodiments, thedependency data is based one of the group consisting of the transactionsand the device responses. In some embodiments, each of the agentsassociated with testing data that is dependent is configured tocontinuously poll an associated input lookout port for the dependencydata and each of the agents associated with testing data that isdepended upon is configured to automatically send the dependency data onan associated output lookout port. In some embodiments, the systemfurther comprises a dispatcher including an agent table and coupled witha reference model and a scoreboard, wherein the dispatcher is configuredto input data comprising a copy of each of the one or more transactionsand the one or more device responses to the transactions, identifywhether each portion of the data is one of the copies of each of the oneor more transactions or one of the device responses based on the agenttable and route each portion of data identified as one of the copies ofeach of the one or more transactions to the reference model and eachportion of data identified as one of the one or more device responses tothe scoreboard. In some embodiments, each of the plurality of agentsfurther comprise a monitor configured to sample the transactions and thedevice responses on an interface between the agent and the device undertest, to automatically forward the sampled transactions and deviceresponses to the dispatcher and to send the dependency data. In someembodiments, each of the plurality of agents further comprise asequencer configured to receive the dependency data and to produce oneof the transactions for testing the device under test, and furtherwherein each of the plurality of agents further comprise a genericdriver coupled with the sequencer, wherein the driver is configured toreceive the transaction from the sequencer. In some embodiments, each ofthe plurality of agents further comprise a transporter coupled with themonitor and the driver and coupled with the device under test via theinterface, wherein the transporter is configured to perform a handshakeprotocol with the device under test over the interface based on a classof the interface. In some embodiments, the device under test is avirtual emulation of an electronic device.

A second aspect is directed to a testbench builder for generating atestbench for verification of a device under test, wherein the testbenchbuilder is stored on a non-transitory computer readable medium andconfigured to perform a method comprising reading an interfaceconfiguration file associated with the device under test and identifyinga plurality of interfaces associated with the device under test definedin the interface configuration file and generating a verificationenvironment including a plurality of agents coupled with the deviceunder test such that there is an agent for each of the interfaces in theinterface configuration file, wherein the plurality of agents eachcomprise one or more loopback ports and is configured to perform one ofoutputting testing data to or inputting testing data from the deviceunder test such that each of the agents are associated with a portion ofthe testing data, wherein at least one of the portions is dependent onat least one other of the portions with respect to testing the deviceunder test, and further wherein one of the loopback ports of a firstagent of the agents that is associated with the at least one of theportions is coupled with one of the loopback ports of a second agent ofthe agents that is associated with the at least one other of theportions for transmitting dependency data between the one of the agentsand the another of the agents. In some embodiments, outputting thetesting data comprises outputting one or more transactions to the deviceunder test and inputting the testing data comprises inputting one ormore device responses to the transactions from the device under test. Insome embodiments, a second of the loopback ports of the first agent iscoupled with a second of the loopback ports of the second agent suchthat there are two connections between the first agent and the secondagent via the loopback ports. In some embodiments, the first agent iscoupled with one or more additional agents of the agents via theloopback ports of the first agent and the additional agents such thatthe first agent is coupled to a plurality of the agents via the loopbackports of the first agent. In some embodiments, each connection couplingtwo of the loopback ports has a traffic direction configured such thatan input lookout port of the ports of the agent associated with thetesting data that is dependent receives the dependency data from anoutput lookout port of the lookout ports of the agent associated withthe testing data that is depended upon. In some embodiments, thedependency data is based one of the group consisting of the transactionsand the device responses. In some embodiments, each of the agentsassociated with testing data that is dependent is configured tocontinuously poll an associated input lookout port for the dependencydata and each of the agents associated with testing data that isdepended upon is configured to automatically send the dependency data onan associated output lookout port. In some embodiments, whereingenerating the verification environment further comprises generating adispatcher including an agent table and coupled with a reference modeland a scoreboard, wherein the dispatcher is configured to input datacomprising a copy of each of the one or more transactions and the one ormore device responses to the transactions, identify whether each portionof the data is one of the copies of each of the one or more transactionsor one of the device responses based on the agent table and route eachportion of data identified as one of the copies of each of the one ormore transactions to the reference model and each portion of dataidentified as one of the one or more device responses to the scoreboard.In some embodiments, each of the plurality of agents further comprise amonitor configured to sample the transactions and the device responseson an interface between the agent and the device under test, toautomatically forward the sampled transactions and device responses tothe dispatcher and to send the dependency data. In some embodiments,each of the plurality of agents further comprise a sequencer configuredto receive the dependency data and to produce one of the transactionsfor testing the device under test, and further wherein each of theplurality of agents further comprise a generic driver coupled with thesequencer, wherein the driver is configured to receive the transactionfrom the sequencer. In some embodiments, each of the plurality of agentsfurther comprise a transporter coupled with the monitor and the driverand coupled with the device under test via the interface, wherein thetransporter is configured to perform a handshake protocol with thedevice under test over the interface based on a class of the interface.In some embodiments, generating the verification environment comprisesgenerating the connection between the loopback ports based on interfaceparameters of the interface associated with the agents as defined in theinterface configuration file. In some embodiments, the device under testis a virtual emulation of an electronic device.

A third aspect is directed to a method of testing a device under testwithin a verification environment of a testbench. The method comprisessending dependency data from an output port of loopback ports of a firstagent to an input port of loopback ports of a second agent within theverification environment, continuously polling the input port of thesecond agent for the dependency data with a second sequencer of thesecond agent, producing dependent testing data for testing the deviceunder test based on the dependency data with the second sequencer of thesecond agent and receiving the dependent testing data from the secondsequencer and sending the dependent testing data to the device undertest with a second driver of the second agent. In some embodiments, themethod further comprises generating independent testing data for testingthe device under test with a first sequencer of the first agent andreceiving the independent testing data from the first sequencer andsending the independent testing data to the device under test with afirst driver of the first agent, wherein the dependency data is based onthe independent testing data. In some embodiments, the dependent testingdata is dependent upon the independent testing data with respect to thetesting of the device under test. In some embodiments, the methodfurther comprises inputting independent testing data for testing thedevice under test from the device under test with a first monitor of thefirst agent, wherein the dependency data is based on the independenttesting data. In some embodiments, the dependent testing data isdependent upon the independent testing data with respect to the testingof the device under test. In some embodiments, the method furthercomprises sending the dependency data from a second output port of theloopback ports of the first agent to an input port of loopback ports ofa third agent within the verification environment. In some embodiments,the dependency data is sent to the second agent and the third agentsimultaneously. In some embodiments, the method further comprisessending additional dependency data from an output port of the loopbackports of the second agent to an input port of the loopback ports of thefirst agent. In some embodiments, the device under test is a virtualemulation of an electronic device.

A fourth aspect is directed to an agent within a verificationenvironment of testbench system stored on a non-transitory computerreadable medium for testing operation of a device under test. The agentcomprises one or more loopback ports including one or more input portsand one or more output ports, and configured to couple with one or moreadditional agents within the verification environment, a monitor coupledwith the output ports and configured to input testing data from thedevice under test and forward dependency data based on the input testingdata to the output ports if one or more of the output ports are coupledwith at least one of the additional agents, a driver configured tooutput testing data to the device under test and a sequencer coupledwith the driver and configured to receive the dependency data from theinput ports if one or more of the input ports are coupled with at leastone of the additional agents and to produce the output testing data fortesting the device under test based on the dependency data. In someembodiments, the loopback ports are unidirectional, the input ports areconfigured to receive data traffic and the output ports are configuredto output data traffic. In some embodiments, the dependency data is theinput testing data. In some embodiments, the agent further comprises atransporter coupled with the monitor and the driver and coupled with thedevice under test, wherein the transporter is configured to perform ahandshake protocol with the device under test.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing will be apparent from the following more particulardescription of example embodiments of the invention, as illustrated inthe accompanying drawings in which like reference characters refer tothe same parts throughout the different views. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingembodiments of the present invention.

FIG. 1 illustrates a testbench builder system according to someembodiments.

FIG. 2 illustrates a testbench according to some embodiments.

FIG. 3 illustrates a method of generating a test bench according to someembodiments.

FIG. 4 illustrates a block diagram of an exemplary testbench builderdevice configured to implement the testbench builder applicationaccording to some embodiments.

FIG. 5 illustrates an agent according to some embodiments.

FIG. 6 illustrates a method of testing a device under test within averification environment of a testbench according to some embodiments.

FIG. 7A illustrates a first process including a two-way handshakeprotocol and transaction transmission according to some embodiments.

FIG. 7B illustrates a second process including a simple or one-wayhandshake protocol without flow control and transaction transmissionaccording to some embodiments.

FIG. 7C illustrates a third process including a one-way handshakeprotocol with flow control, transaction transmission and start/end ofdata marking signals according to some embodiments.

FIG. 8 illustrates an agent according to some embodiments.

FIG. 9 illustrates a method of testing a device under test within averification environment of a testbench according to some embodiments.

FIG. 10A illustrates a first process of monitoring a two-way handshakeprotocol and transaction transmission according to some embodiments.

FIG. 10B illustrates a second process of monitoring a simple or one-wayhandshake protocol without flow control and transaction transmissionaccording to some embodiments.

FIG. 10C illustrates a third process of monitoring a one-way handshakeprotocol with flow control, transaction transmission and start/end ofdata marking signals according to some embodiments.

FIG. 11 illustrates a testbench according to some embodiments.

FIG. 12 illustrates a method of testing a device under test within averification environment of a testbench according to some embodiments.

FIG. 13 illustrates a testbench with agents having coupled loopbackports according to some embodiments.

FIG. 14 illustrates a method of testing a device under test within averification environment of a testbench according to some embodiments.

FIG. 15 illustrates a method of testing a device under test within averification environment of a testbench according to some embodiments.

DETAILED DESCRIPTION OF THE INVENTION

In the following description, numerous details are set forth forpurposes of explanation. However, one of ordinary skill in the art willrealize that the invention can be practiced without the use of thesespecific details. Thus, the present invention is not intended to belimited to the embodiments shown but is to be accorded the widest scopeconsistent with the principles and features described herein.

Embodiments described herein are directed to a testbench for testing adevice under test (DUT), wherein the testbench has a verificationenvironment that is able to include one or more of a reference model, ascoreboard, a dispatcher and a customized agent for each interface thatthe DUT needs to receive input from and/or transmit output on. Thetestbench system is able to comprise agents with generic drivers,generic monitors, loopback ports and/or interface specific transporterswhich handle interface/DUT specific handshake protocols and/or themonitoring thereof. The testbench system is able to be generated by atestbench builder configured to automatically generate a testbench for adevice under test (DUT), wherein the generated testbench has averification environment comprising one or more of a reference model, ascoreboard, a dispatcher and a customized agent for each interface thatthe DUT needs to receive input from and/or transmit output on.Specifically, the testbench builder is able to first automaticallycreate generic agents including generic drivers, sequencers, loopbackports and/or generic monitors for each interface and then automaticallycustomize the generic agents based on their corresponding interface suchthat the agents meet the requirements of the interface for the DUT. Atthe same time, the testbench builder is able to integrate all thecustomized agents into the verification environment, integrate theverification environment with register transfer level (RTL) ports,binding the outputs and/or inputs of the agents to other agents and/orRTL ports, and preparing a random sample test case for testing the DUTwith the generated testbench. As a result, the testbench system providesthe benefit of enabling the generic drivers and/or generic monitors tobe generated independent of the interface characteristics such ashandshake protocol. Additionally, the testbench builder is able toautomatically create the entire testbench in minutes based on aninterface file including the necessary interfaces and theircharacteristics for the DUT.

FIG. 1 illustrates a testbench builder system 100 according to someembodiments. As shown in FIG. 1, the system 100 comprises a testbenchbuilder device 102 storing a testbench builder application 103 andcoupled with one or more DUTs 104 via one or more networks 106.Alternatively, the testbench builder application 103 is able to bestored on an external database that is accessed by the testbench builderdevice 102 via the networks 106. In some embodiments, the networks 106comprise a wireless network. Alternatively, the networks 106 are ablecomprise a wired network or any combination of wired and wirelessnetworks. In some embodiments, the DUT 104 is front end representationof the device implemented in RTL or other programming language.Alternatively, the DUT 104 is able to be a physical device, such as aprototype device. The DUT 104 is able to be stored on a memory of and/orincorporated into the testbench builder device such that the network 106comprises an internal or local network of the device 102 such as theinterfaces described herein. For example, the DUT 104 generated in RTLor another programming language is able to interact with the testbench202 (see FIG. 2) generated by the testbench builder application 103 inUVM™ or other language via one or more interfaces 222 (see FIG. 2).Alternatively, in such embodiments the DUT 104 is able to be stored onthe memory of one or more additional computing devices (e.g a server,computer) such that the networks 106 comprise external networks couplingtogether the testbench builder device 102 and DUT 104 via the additionalcomputing devices. To put it another way, the DUT 104 is able tocomprise hardware, emulation software or combination thereof. Forexample, the DUT 104 is able to be a piece of code (e.g. RTL, gatelevel, System C models) which provides or emulates the functionality ofa device that is desired to be tested. Although as shown in FIG. 1, onlya single DUT 104 is coupled to the testbench builder device 102, anynumber of DUTs 104 and/or devices 102 are contemplated.

FIG. 2 illustrates a testbench 202 according to some embodiments. Asshown in FIG. 2, the testbench 202 includes a verification environment204 comprising one or more agents 206, one or more reference models 208and one or more scoreboards 210 coupled with one or more DUTs 212 viaone or more interfaces or virtual interfaces 222. In some embodiments,the verification environment 204 and the components therein areimplemented in one or more verification methodologies (e.g. universalverification methodology (UVM™)). Although in FIG. 2 only two agents206, two interfaces 222 and one DUT 212 are shown, any number of agents206, interfaces 222 and DUTs 212 are contemplated. For example, in someembodiments the verification environment 204 comprises at least oneagent 206 for each interface 222, wherein the DUT 212 is able tocomprise numerous associated interfaces 222. Additionally, althoughdescribed separately herein, in some embodiments one or more of thecomponent of the verification environment 204 are able to be combinedinto a single component. For example, the one or more reference models208 and the one or more scoreboards 210 are able to be combined into oneor more single entities that perform the functions of both. Generally,each interface 222 (input or output) requires both control and datasignals for communication. The data signals carry the information uponwhich the DUT 212 operates and the control signals define thesignificance of the data signals on that cycle. As also shown in FIG. 2,the agents 206 each comprise one or more sequencers 214, one or moremonitors 216 and one or more drivers 220.

The monitors 216 are able to observe and/or sample pin level activityand converts its observations (e.g. observed output data signals fromthe agents 206 and/or DUT 212) to a format that is used within theverification environment 204 by the agents 206, reference model 208and/or scoreboard 210. The drivers 220 are able to convert transactionsreceived from the sequencers 214 for the device under test 212 from aformat that is used within the verification environment 204 by theagents 206, reference model 208 and/or scoreboard 210 to a pin levelconfiguration of the device under test 212. Alternatively, the agents206 and/or testbench 202 are able to comprise more or less componentssuch that one or more of the components are able to be replicated,omitted and/or new components are able to be added. For example, thetestbench 202 is able to comprise a database of one or more test caseseach including one or more stimulus patterns based on the DUT 212 fortesting the DUT 212 with the testbench 202. In some embodiments, thetestbench 202 and/or environment 204 is able to be coupled/integratedwith the DUT 212 on a register transfer level. Alternatively, thecoupling/integration of the testbench 202 and the DUT 212 is able to bewith other communication levels.

In operation, the verification environment 204 provides the platform oroperating system in which the agents 206, reference model 208 andscoreboard 210 are able to interoperate. Specifically, based on a testcase being implemented by the testbench 202 and/or environment 204, thedriver 220 of one or more of the agents 206 (e.g. agent 1) accepts datastimulus or testing data generated by the sequencer 214 in the form of atransaction and drives the data onto an interface 222 a with which theagent 206 is associated (using a protocol for that DUT 212 and/orinterface 222 a). In other words, the sequencer 214 is able tocoordinate the execution of stimulus in the form of sequences andsequence items from a parent sequence (e.g. test case), ultimatelyfeeding the driver 220 with transactions. Additionally, the monitor 216of the one or more of the agents 206 sends a copy of the data stimulusto the reference model 208 of the one or more agents 206. This referencemodel 208 is able to comprise one or more transfer functions configuredsuch that it mimics an idealized operation of the DUT 212 for generateddata stimulus. In other words, the reference model 208 is able to beconfigured to represent the behavior of a device under test 212 and/or aparticular feature or features of the device under test 212 (e.g. commonfeature patterns) and in that way transform received transactions into“ideal” output transactions. As a result, upon receiving the datastimulus the reference model 208 is able to send modified reference datato the scoreboard 210, wherein the modified reference data representsthe ideal output data for an ideal DUT 212 based on the inputted datastimulus. The scoreboard 210 is able to be configured to compare actualand expected values of the data received from the reference module 208and the data received from the DUT 212 (e.g. via the monitor 216 of anagent 206). In some embodiments, the scoreboard 210 is also able torecord statistical information about the data received and/or createreports based on that information.

At the same time, the DUT 212 receives the data stimulus from the driver220 via the associated the interface 222 a, performs an operation on thedata and outputs the resulting DUT data on an appropriate outputinterface 222 b. As a result, this outputted DUT data is able to besampled by the monitor 216 of the agent 206 associated with the outputinterface 222 b and sent to the scoreboard 210. The scoreboard 210 isthen able to compare the DUT data to the reference data in order todetermine any differences in behavior of the idealized DUT representedby the reference model 208 and the DUT 212 that is currently beingtested. Specifically, based on these differences the scoreboard 210 isable to determine whether the DUT 212 is behaving within a set ofoperational limits for the test case and/or any operational errors thatare indicated by the DUT data not matching the reference data. As aresult, the testbench 202 is able to emulate a real world environment(e.g. test case) for the DUT 212 and ensure that the operation of theDUT 212 within that environment meets the expected operationalstandards. Additionally, it should be noted that although the operationdescribed only included a DUT input and response, multiple inputs and/orresponses (involving multiple agents 206 and/or interfaces 222) insequence and/or in parallel are possible. For example, the referencemodel 208 is able to receive duplicates of all transactions or stimulustransmitted from one or a plurality of agents 206 to the DUT 212 andproduce expected or ideal output transactions for all such receivedduplicates. Similarly, the scoreboard 210 is able to receive allexpected or ideal output transactions from the reference module 208 aswell as all transactions or stimulus transmitted from the DUT 212 to oneor a plurality of the agents 206 such that all the correspondingtransactions can be compared.

FIG. 11 illustrates an alternate embodiment of the testbench 202according to some embodiments. The testbench 202 of FIG. 11 is able tobe substantially similar to the testbench 202 of FIG. 2 except for thedifferences described herein. In particular, as shown in FIG. 11 insteadof being coupled with either the reference model 208 or the scoreboard210 directly as in FIG. 2, the agents 206 (e.g. via the monitors 216)are each coupled to the dispatcher 224 which is coupled to the referencemodel 208 and the scoreboard 210. This dispatcher 224 is able tocomprise an agent table or database 226 that associates the agents 206and/or their associated interfaces 222 a, 222 b (e.g. via the address ofthe ports of the dispatcher 224 that coupled to the agents 206) with thereference model 208 or the scoreboard 210. If the agent/interfacesreceives device responses (e.g. modified transactions) from the DUT 212(e.g. interface 222 b), it is an “input” agent/interface that isassociated with the scoreboard 210. Otherwise, if the agent/interfacetransmits transactions to the DUT 212 (e.g. interface 222 a), it is an“output” agent/interface that is associated with the reference model208. In other words, the associations in the agent table 224 representswhich of the reference model 208 or the scoreboard 210 the agents 206would be coupled directly to if the dispatcher 224 were omitted like inFIG. 2. In some embodiments, the agent table 226 comprises associationsof the addresses of the ports that receive the data from the agents 206with the address of the port coupled to the scoreboard 210 or theaddress of the port coupled to the reference model 208. Additionally, insome embodiments the agent table 226 is generated by the builderapplication based on the interface parameters and the binding of theports within the verification environment.

In operation, unlike FIG. 2, the monitor 216 of the one or more of theagents 206 sends the copy of the data stimulus to the dispatcher 224(not directly to the reference model 208), which then identifies thedata as a transaction and routes the data stimulus to the referencemodel 208 based on the agent database 226. Also unlike FIG. 2, theoutputted DUT data (e.g. device response) is sampled by the monitor 216of the agent 206 and sent to the dispatcher 224 (not directly to thescoreboard 210), which then identifies the data as a device response androutes the response to the reference model 208 based on the agentdatabase 226. Alternatively, the identification and/or routing of thedata is able to be performed based on the packet data itself (e.g.header) without the agent table 224. In either case, the dispatcher 224is able to act as a central routing hub thereby simplifying theconnectivity required within the verification environment 204. Similarto FIG. 2, upon receiving the data stimulus the reference model 208 isable to send modified reference data to the scoreboard 210, wherein themodified reference data represents the ideal output data for an idealDUT 212 based on the inputted data stimulus. Then the scoreboard 210 isable to compare actual and expected values of the data received from thereference module 208 and the data received from the DUT 212 (e.g. viathe dispatcher 224).

FIG. 12 illustrates a method of testing a device under test within averification environment of a testbench according to some embodiments.Although described separately, one or more of the steps of the methodsof FIGS. 6, 9, 12, 14 and/or 15 are able to be combined into a singlemethod. For example, a method of operation of the testbench 202 orverification environment 204 as a whole is able to comprise acombination of one or more of the steps of all of the methods of FIGS.6, 9, 12, 14 and 15 depending on the types of components (e.g. agents,transporters, dispatchers, loopback ports) within the environment 204.As shown in FIG. 12, the dispatcher 224 inputs data from the monitors216 of a plurality of agents 206 within the verification environment 204at the step 1202. The data input by the dispatcher 224 is able to bedata transmitted on the interface 222 associated with each of the agents206 and sampled by the monitor 216 of that agent 206, wherein aftersampling, the monitor 216 forwards the data to the dispatcher 224. Insome embodiments, the monitors 216 are able to be configured toautomatically forward the sampled data (or a copy thereof) to a mailboxor queue of the dispatcher 224. Further, as described in FIGS. 6 and 9below, the sampling by the monitors 216 and driving of transactions bythe drivers 220 is able to be controlled or operate in concert with theassociated transporters 506/806 (see FIGS. 5 and 8). As a result, thedata is able to comprise transactions transmitted by adriver/transporter of an agent 206 onto an interface 222 to the DUT 212or responses to a transaction generated and transmitted by the DUT 212to an agent 206 via an interface 222.

The dispatcher 224 identifies whether each portion of the data is atransaction output by a driver/transporter (or a copy thereof) or adevice response to a transaction output by the DUT 212 (or a copythereof) based on the agent table 226 at the step 1204. In particular,the dispatcher 224 is able to look up the agent 206 or interface 222that is the source/destination of the data (e.g. based on the portaddress of the port that received the data) within the agent table 226and check whether the agent 206 or interface 222 is associated in thetable with the scoreboard 210 or the reference model 208. For example,if the agent/interface is associated with the scoreboard 210, it is an“input” agent/interface that receives responses from the DUT 212 and ifthe agent/interface is associated with the reference model 208, it is an“output” agent/interface that transmits transactions to the DUT 212. Thedispatcher 224 routes each portion of data identified as a transactionoutput by a driver/transporter to a reference model 208 within theverification environment and each portion of data identified as a deviceresponse to a transaction output by the DUT 212 to a scoreboard 210within the verification environment 204 at the step 1206. In otherwords, based on whether the data is “input” or “output” data in theagent table 226 the dispatcher 224 is able to transmit the data to theport coupled with the scoreboard 210 or the reference model 208. As aresult, the method provides the benefit of having a central dispatcher224 that reduces the connection complexity of the verificationenvironment 204. In particular, the dispatcher 224 provides a singlecomponent that all the agents 206 are able to be coupled andautomatically send data to instead of each agent needing a separateconnection established to either the reference model 208 or a singleline to the scoreboard 210. As a result, the dispatcher 224 is able toefficiently route the data either on a single connection to thereference model 208 or a single line to the scoreboard 210.

FIG. 13 illustrates an alternative embodiment of the testbench 202according to some embodiments. The testbench 202 of FIG. 13 is able tobe substantially similar to the testbench 202 of FIGS. 2 and/or 11except for the differences described herein. In particular, as shown inFIG. 13 one or more of the agents 206 within the verificationenvironment 204 are able to comprise and/or be coupled with each othervia one or more loopback ports 228. As a result, instead of needing atop level multilayer or virtual sequencer in order to solve testing data(e.g. transactions, device responses) dependency issues amongst theagents 206, the agents 206 are able to use the loopback ports 228 tosend dependency data directly and solve the dependency issues“peer-to-peer.” In some embodiments, all of the agents 206 within theenvironment 204 comprise one or more loopback ports 228. Alternatively,less than all of the agents 206 comprise loopback ports 206. Theloopback ports 228 are able to be substantially similar to the otherports within the verification environment 204 except that they arededicated to coupling two or more agents 206 together within theenvironment 204.

In some embodiments, some or all of the agents 206 comprise one or moreinput loopback ports for inputting data (e.g. dependency data) and oneor more output loopback ports for outputting data (e.g. dependencydata). Alternatively, some or all of the agents 206 are able to compriseonly one or more input or only one or more output loopback ports 228. Asshown in FIG. 13, a single agent (agent 1) is coupled to a single agent(agent 2) via the loopback ports 228. Alternatively, any of the agents206 are able to be coupled with zero, one or a plurality of the otheragents 206 within the environment 204 wherein the loopback portconnections are able to be all outputting data from the agent to theother agents, all inputting data to the agent from the other agents or acombination of input and output connections. Further, although as shownin FIG. 13 the loopback ports of the agents 1 and 2 are coupled via asingle connection, a plurality of connections are able to be madebetween any two agents 206. For example, a first connection is able tosend dependency data from agent 1 to agent 2, whereas a secondconnection is able to send dependency data from agent 2 to agent 1.

This dependency data is able to be data that solves or reflects adependent or conditional relationship between testing data (e.g.transactions, device responses) sent between the agents 206 and the DUT212. Two sets or increments of testing data have a dependencyrelationship if the processing of one of the sets of testing data (withrespect to testing the DUT 212) requires data of or related to the otherset of testing data such that the dependent testing data cannot beimplemented/processed (by the agent 206 and/or DUT 212) until thedepended upon testing data has been implemented/processed such that therequired dependency data can be determined from the depended upontesting data. An example of such a pair of dependent testing data is aquery response pair, wherein the response testing data is dependent onwhat the query data (i.e. what the query is asking) The dependencies canbe based on some or all of the content of the depended upon testing data(e.g. what is the query, end of packet, start of packet, sourceidentifier, destination identifier), the processing of the depended upontesting data (e.g. when was it sent/synchronization data, has it beenreceived at the destination, did it contain an error), data derived fromthe content of the depended upon data (e.g. what is the size of thedepended upon data) and/or other testing data characteristics that areable to be depended upon. In other words, testing data is able to bedependent on other testing data in any case where the processing ormanipulation of a first set of testing data requires some or all of theprocessing or manipulation a second set of testing data.

Similar to the permutations of the connections between the agents 206via the loopback ports 228, the dependencies between testing data isable to be one to one, one to a plurality and/or mutual dependencies(e.g. multiple dependencies between the same two sets of testing data),wherein the “direction” of the dependencies is able to be all onedirection or a combination of directions (e.g. a, b and c dependent on dor d dependent on a, b and c; a and b dependent on d and d dependent onc; a dependent on b and b dependent on a). The dependency data itselfthat is sent between the agents 206 via the loopback ports 228 is ableto comprise the transactions, the device responses and/or portions orderivations thereof. For example, the dependency data for aquery/response dependency between two sets of testing data is able to bethe query itself, which is sent to the second agent for generating aresponse to the query. Alternatively, the dependency data for twoconditional transactions is able to be a portion of one of thetransactions (e.g. start of packet, end of packet, packet identifier,source port, destination port, packet size, or other packet fieldvalues) that is used to parse or otherwise process the second of thetransactions. Alternatively, the dependency data for two conditionaltransactions is able to be an indication that one of the transactionshas been send to or received by the DUT 212 such that the DUT 212 isready to receive the second of the transactions. Essentially, thedependency data is able to be any data that solves the unknown orvariable in the second of the transactions that created/caused thedependency between the testing data.

In operation, if an agent 206 is coupled with one or more other agents206 via the loopback ports 228 for outputting dependency data to theother agents 206, the monitor 216 is able to be configured toautomatically output sampled testing data (e.g. device response from theDUT 212) to the other agents 206 via the output loopback port 228coupled to the other agents 206. Alternatively or in addition, if anagent 206 is coupled with one or more other agents 206 via the loopbackports 228 for outputting dependency data to the other agents 206, thesequencer 214 is able to be configured to automatically output generatedtesting data (e.g. a transaction for the DUT 212) to the other agents206 via the output loopback port 228 coupled to the other agents 206.Alternatively or in addition, if an agent 206 is coupled with one ormore other agents 206 via the loopback ports 228 for inputtingdependency data to from other agents 206, the sequencer 214 is able tobe configured to automatically input or poll the loopback ports 228 forthe dependency data from the loopback ports 228 of the other agents 206and to adjust or generate testing data to be output to the DUT 212 (viathe driver 220) based on the input dependency data.

In some embodiments, the inputting or outputting of dependency data bythe monitor 216 and/or sequencer 214 is able to occur automaticallyevery cycle. Alternatively, it is able to occur automatically ormanually every cycle, periodic cycles, based on a trigger event, and/orother cycle schedules. In embodiments wherein the agent 206 comprises atransporter 506/806 as shown in FIGS. 5 and 8, the transporter 506/806is able to control the outputting and/or inputting of the dependencydata in the same manner in which it controls the outputting and/orinputting of the transaction or device response data as describedherein. Alternatively, even if a transporter 506/806 is present in theagent 206, the monitor 216 and/or sequencer 214 are able to operateindependently with respect to the dependency data and loopback ports 228as described above. In some embodiments, the dependency data is able tobe broadcast or multicast on multiple output loopback ports 228simultaneously. Alternatively, the dependency data is able to be sentout on a plurality of loopback ports 228 sequentially (e.g. roundrobin), via a priority scheme and/or upon request.

FIG. 14 illustrates a method of testing a device under test within averification environment of a testbench according to some embodiments.Although described separately, one or more of the steps of the methodsof FIGS. 6, 9, 12, 14 and/or 15 are able to be combined into a singlemethod. For example, a method of operation of the testbench 202 orverification environment 204 as a whole is able to comprise acombination of one or more of the steps of all of the methods of FIGS.6, 9, 12, 14 and 15 depending on the types of components (e.g. agents,transporters, dispatchers, loopback ports) within the environment 204.As shown in FIG. 14, a first agent 206 (via the monitor 216 and/orsequencer 214) sends dependency data from an output port of its loopbackports 228 to an input port of loopback ports 228 of one or more secondagents 206 within the verification environment 204 at the step 1402. Insome embodiments, the sending of the dependency data comprises(simultaneously or otherwise) sending the data to a plurality of inputloopback ports 228 of a plurality of agents 206. In some embodiments,the dependency data is related to testing data sampled by the monitor216 (e.g. a device response/query) from the interface 222 between thefirst agent 206 and the DUT 212. For example, in some embodiments themethod further comprises the monitor 216 of the first agent 206inputting testing data (e.g. a sampled device response) from the DUT 212such that the dependency data of step 1402 is based on the input testingdata. Indeed, in some embodiments the dependency data is able to matchthe testing data sampled by the monitor 216. Additionally, in someembodiments this exemplary operation of the monitor 216 is able to becontrolled by a transporter 806 of the first agent 206 as described inthe method of FIG. 9.

Alternatively, the dependency data is able to be related testing datagenerated by the sequencer 214 (e.g. a new transaction) and sent to theDUT 212 via the interface 222 between the first agent 206 and the DUT212. For example, in some embodiments the method further comprises thesequencer 214 of the first agent 206 generating new testing data (e.g.the new transaction) for testing the DUT 212 and the driver 220 of thefirst agent 206 receives the testing data from the sequencer 214 andsends it to the DUT 212 such that the dependency data of step 1402 isbased on the new testing data. Further, this new testing data is able tobe independent testing data or testing data that was dependent on adifferent set of testing data from a different agent 206. Moreover, insome embodiments this exemplary operation of the sequencer 214 anddriver 220 is able to be controlled by a transporter 506 of the firstagent 206 as described in the method of FIG. 6. The sequencer 214 of thesecond agent(s) 206 polls the input port 228 for the dependency data atthe step 1404. The sequencer 214 of the second agent(s) 206 produce orgenerate dependent testing data (e.g. a new transaction) for testing theDUT 212 based on the dependency data at the step 1406. The driver 220 ofthe second agent(s) 206 receive the dependent testing data from thesequencer 214 and send the dependent testing data to the DUT 212 at thestep 1408. In particular, in some embodiments a sequence thatcreates/builds transactions is able to be registered in the sequencer214 such that the sequencer 214 is able to execute the sequence andthereby generate the transactions. In such embodiments, the polling ofthe dependency data and/or producing of dependent testing data is ableto be in the sequence registered in the sequencer 214.

In some embodiments, the method further comprises the first agent 206receiving dependency data from one or more other agents 206 in the samemanner that the second agent(s) 206 received such data from the firstagent 206. Indeed, the dependency data sent by the first agent 206 isable to be based on dependency data received by the first agent 206 froma different agent 206 via the loopback ports 228. Further, in someembodiments, one or more of the second agent(s) 206 send dependency datato the first agent 206 either before or after the first agent 206 sendsits dependency data. Accordingly, the method provides the advantage ofenabling dependency issues that arise during the testing of the DUT 212to be solved on a peer to peer level between the agents 206 via theloopback ports 228 and their connections removing the need for a toplevel virtual or multi-layer sequencer to be generated in the virtualenvironment 204.

In some embodiments, the monitor 216 of one or more of the agents 206 isconfigured to determine a timestamp value for testing data (e.g.transactions) sampled by the monitor 216, wherein the timestamp valueindicates the time when the testing data was sampled from the interface222 by the monitor. As a result, this timestamp value for the testingdata is able to be referenced by any of the agents 206 and/or othercomponents (e.g. scoreboard, reference module, dispatcher) of theverification environment 204 in order to determine the latency of thetesting data in reaching the agents 206 and/or components. Specifically,in such embodiments the agents 206 and/or other components are able toread the timestamp value and compare it to the current time in order todetermine the amount of time (e.g. latency value) that elapsed betweenwhen the testing data was sampled and when it reached the agents 206and/or other components (i.e. the verification environment latency forthe testing data). The agents 206 and/or other components are then ableto adjust the timing of their actions based on this latency value. Theseactions are able to comprise the generation and/or driving of testingdata to the DUT 212, the initiation of handshake protocol with the DUT212, the generation and/or transmission of dependency data to one ormore different agents 206 via loopback ports 228, and/or any otheroperations performed by the agents 206 and/or the other components ofthe verification environment 204.

For example, if a first agent 206 is configured to receive a query fromthe DUT 212 and a second agent is configured to send a response to theDUT 212 for the query after a predetermined time period (e.g. 15-25clock cycles), the monitor 216 of the first agent is able to determinethe timestamp value of the query. Then, when the second agent receivesthe query it is able to determine the latency value of the query basedon the timestamp value and the time it was received. Finally, the secondagent 206 is able to determine how much more time must pass (if any)before the predetermined time period has elapsed by subtracting thelatency value from the predetermined time period such that the secondagent 206 is able to ensure that the response to the query is sent tothe DUT 212 at a time when or after the predetermined time period haselapsed. As a result, the timestamps provide the advantage of enablingeach agent 206 and/or other component within the verificationenvironment 204 to determine the latency of any testing data that theyreceive and adjust for that latency if necessary. In particular, thisable to be done without the use of a separate component (e.g. a virtualor multilayer sequencer) that must separately control the agents 206and/or other components in order to adjust for the latency issues.

In some embodiments, the sequencer 214 of one or more of the agents 216is configured to read the timestamp value, determine the latency valuebased on the current time and adjust operation based on the latencyvalue. Alternatively, the driver 220, monitor 216, transporter 506 (seeFIG. 5), or other element of the agents 206 is able to read thetimestamp value, determine the latency value based on the current timeand adjust operation based on the latency value. In some embodiments,the timestamp value is added to a header of the testing data such thatsubsequent agents 206 and/or the DUT 212 are able to read the header ofthe testing data in order to determine the timestamp value.Alternatively or in addition, the timestamp value is able to be storedand/or transmitted separately from the testing data to which it relates.For example, the timestamp value is able to be added to the dependencydata related to the testing data such that the value is able to beaccessed from the dependency data.

FIG. 15 illustrates a method of testing a device under test within averification environment of a testbench according to some embodiments.Although described separately, one or more of the steps of the methodsof FIGS. 6, 9, 12, 14 and/or 15 are able to be combined into a singlemethod. For example, a method of operation of the testbench 202 orverification environment 204 as a whole is able to comprise acombination of one or more of the steps of all of the methods of FIGS.6, 9, 12, 14 and 15 depending on the types of components (e.g. agents,transporters, dispatchers, loopback ports) within the environment 204.As shown in FIG. 15, a first agent 206 performs one of outputting thetesting data to or inputting the testing data from the DUT 212 via theinterface 222 coupling the first agent 206 to the DUT 212 at the step1502. A monitor 216 of the first agent 206 samples testing data on theinterface 222 between the DUT 212 and a first agent 206 at the step1504. The monitor 216 generates a timestamp for the testing data at thestep 1506. Specifically, the timestamp is able to indicate a sampledtime at which the testing data was sampled by the monitor 216 and thusfirst becomes active within the verification environment 204.

In some embodiments, the method further comprises receiving sequencerdata associated with the testing data with a sequencer 214 of a secondagent 206 coupled to the first agent 206 (e.g via loopback ports 228)and comparing the sampled time associated with the testing data with acurrent time to determine a latency of the received sequencer data. Thecomparison is able to be performed by the sequencer 214 or any othercomponent of the second agent 206. In some embodiments, the methodfurther comprises generating new testing data with the sequencer 214based on the received sequencer data and adjusting when a driver 220 ofthe second agent 206 drives the new testing data to the DUT 212 with thesequencer 214 based on the latency of the received sequencer data. Inparticular, the adjusting of when the driver 220 drives the new testingdata to the DUT 212 is able to comprise driving the new testing datawhen a time period equal to a predetermined delay value minus thelatency value has elapsed. For example, if the sequencer 214 and/ordriver 220 are configured to drive testing data to the DUT 212 after apredetermined delay period from when the DUT 212 transmitted testingdata (e.g. device response/query) to the verification environment 204,the sequencer 214 and/or driver 220 are able to take in considerationthe latency of the testing data reaching the sequencer 214 and/or driver220 when calculating the predetermined delay period. In someembodiments, the delay period is between 15 and 25 clock cycles.Alternatively, the delay period is able to be less than 15 clock cyclesor greater than 25 clock cycles. Also, in some embodiments the testingdata of the second agent 206 is dependent on the testing data of thefirst agent 206 such that the second agent 206 is unable to output thedependent testing data without first receiving dependency data about thedepended upon testing data of the first agent 206. Indeed, in suchembodiments the dependency data is the same as the sequencer data. Forexample, the dependency data is able to be a transaction that wasreceived by the sequencer 214 as the sequencer data.

Testbench Agent

FIG. 5 illustrates an agent 500 according to some embodiments. Inparticular, the agent 500 is able to be substantially similar to theagent 206 except for the differences described herein. Further, althoughdiscussed separately, the agent 500 is able to replace and/or supplementthe agents in all of the embodiments described herein. Additionally,although shown separately in FIG. 5, the transporter 506 is able tocombined within or a part of the driver 504. As shown in FIG. 5, theagent 500 comprises a sequencer 502, a driver 504, a transporter 506 anda monitor 508, wherein the sequencer 502 and transporter 506 are coupledwith the driver 504, and the driver 504 and transporter 506 are coupledwith the DUT 212 via an interface 222. The transporter 506 is able to beconfigured to handle all handshaking protocol necessary forcommunicating with the DUT 212 over the interface 222 such that thedriver 504 is able to be generic in that it is not configured based onthe handshake protocol of the interface 222. In particular, by removingthe handshaking protocol responsibilities from the driver 504 with thetransporter 506, the driver 504 is able to be automatically generatedfor an interface 222 without any knowledge of the protocols of theinterface 222.

In some embodiments, the agent 500, driver 504 and/or transporter 506are configured to transmit all or a portion of the transaction to theDUT 212 via the interface 222 every clock cycle. Similarly, in someembodiments the transporter 506 is configured to perform the handshakingprotocol with the interface 222 and/or DUT 212 every clock cycle beforepermitting or preventing transmission of the transaction to the DUT 212.Alternatively, the transmission of the transaction and/or performance ofthe handshaking is able to be performed on a transaction basis,operation basis, periodically, on demand, or according to other types ofschedules. In some embodiments, the driver 504 is able to operatewithout the transporter 506 using a default handshake protocol or nohandshake protocol.

FIG. 6 illustrates a method of testing a device under test 212 within averification environment 204 of a testbench 202 according to someembodiments. Although described separately, one or more of the steps ofthe methods of FIGS. 6, 9, 12, 14 and/or 15 are able to be combined intoa single method. As shown in FIG. 6, a sequencer 502 of an agent 500within the verification environment 204 produces a transaction fortesting the DUT 212 at the step 602. The generic driver 504 of the agent500 retrieves and/or receives the transaction from the sequencer 502 atthe step 604. In some embodiments, a new transaction is produced and/orreceived each clock cycle. Alternatively, one or more of thetransactions are able to be multi-cycle such that data related to asingle transaction is transmitted and/or received over multiple cycles.The driver 504 and/or the transporter 506 of the agent 500 performs ahandshake with the DUT 212 (via the interface 222) according to ahandshake protocol at the step 606. In other words, the transporter 506is able to both drive control signals onto and/or sample control signalsfrom an interface 222 in order to effectuate a handshake protocol forthat interface 222 and/or DUT 212. In some embodiments, the handshakeprotocol used is based on interface 222 and/or DUT 212. In someembodiments, the handshake protocol is indicated by the transporterclass for the interface 222 within the interface configuration file.Based on the outcome of the handshake protocol, the driver 504 and/orthe transporter 506 determines if the interface 222 and/or DUT 212 isready to receive data at the step 608. The driver 504 communicates withthe transporter 506 to forward/load the transaction on the interface 222if the outcome of the handshake protocol indicates the interface 222and/or DUT 212 is ready to receive the transaction at the step 610. Insome embodiments, the monitor of the agent 500 also forwards thetransaction to the reference model 208 (either directly or via adispatcher 224) as described above. In some embodiments, thecommunication is a control command received by the driver 504 from thetransporter 506 indicating the outcome of the handshake protocol. Insome embodiments, the driver 504 gives the transaction to thetransporter 506 based on the outcome such that the transporter 506forwards and/or loads the transaction on the interface 222.Alternatively, the driver 504 is able to forward and/or load thetransaction on the interface 222 based on the outcome of the handshakeprotocol. As a result, the method provides the benefit of enabling thedriver 504 to remain generic while still customizing the agent 500 forthe interface 222 and/or DUT 212 by using the transporter 506 to controlthe handshake protocol with the interface 222 and/or DUT 212.

In some embodiments, the method further comprises sending data receivedfrom the DUT 212 to the one or more additional agents coupled to theagent 500 within the environment 204. In such embodiments, the handshakeprotocol used by the transporter 506 is able to be different than ahandshake protocol of a transporter of the one or more additionalagents. As described above, in some embodiments the handshake protocolis one of three handshake protocols consisting of a one-way handshakeprotocol without destination flow control, a two-way handshake protocoland a one-way handshake protocol with destination flow control.Alternatively, any number and/or combination of different or the samehandshake protocols are able to be used. In some embodiments, steps604-610 are performed each clock cycle. Alternatively, if thetransaction is a multi-cycle transaction, step 604 is able to be omittedand only steps 606-610 are performed each subsequent clock cycle untilthe multi-cycle transaction is complete.

FIGS. 7A-7C illustrate three exemplary handshake protocol andtransaction transfer processes according to some embodiments. FIG. 7Aillustrates a first process including a two-way handshake protocol 702and transaction transmission 704 according to some embodiments. Inparticular, the two-way handshake protocol 702 comprises sending a firstsignal “source ready” from the agent 500 to the DUT 212 (via aninterface) and sending a second signal “destination ready” from the DUT212 to the agent 500. According to the handshake protocol 702, the agent500 indicates that it is ready to send data (and/or that all control anddata signals are valid) when it makes “source ready” high and the DUT212 indicates that it is ready to accept data when “destination ready”is high. As a result, when both “source ready” and “destination ready”are both high, the outcome of the protocol indicates that transactiontransmission(s) 704 should be transmitted and when either “source ready”or “destination ready” are low, the outcome of the protocol indicatesthat transaction transmission(s) 704 should not be transmitted or ceasefrom being transmitted from the agent 500 to the DUT 212. This two-wayhandshake protocol enables either party (agent 500 or DUT 212) to stoptransaction transmissions 704 unilaterally and restricts the beginningof transaction transmissions 704 to when both parties indicate that theyare ready. As shown in FIG. 7A, the transaction transmission 704comprises two datasets (data0 and data1) having a payloads of 20:0 and11:0. Alternatively, the transaction transmission 704 is able tocomprise more or less datasets and/or transmission streams each havingmore or less payload and/or quantity of data. In some embodiments, thedriver 504 transmits the transaction transmission 704 to the DUT 212based on the outcome of the handshake protocol 702 (as executed by thetransporter 506). Alternatively, the transporter 506 is able to retrievethe transaction from the driver 504 and transmit the transactiontransmission 704 to the DUT 212 based on the outcome of the handshakeprotocol 702.

FIG. 7B illustrates a second process including a simple or one-wayhandshake protocol without flow control 702 and transaction transmission704 according to some embodiments. In particular, the one-way handshakeprotocol without flow control 702 comprises sending a first signal“valid” from the agent 500 to the DUT 212 (via an interface). Accordingto the handshake protocol 702, the agent 500 indicates that it is readyto send data when it makes “valid” high (and/or that all control anddata signals are valid), but unlike the first process, the agent 500does not wait for, nor does the DUT 212 send, a signal that indicatesthat the DUT 212 is ready to accept data. As a result, when “valid” ishigh, the outcome of the protocol indicates that transactiontransmission(s) 704 should be transmitted and when “valid” is low, theoutcome of the protocol indicates that transaction transmission(s) 704should not be transmitted or cease from being transmitted from the agent500 to the DUT 212. This one-way handshake protocol puts full control inthe agent 500 to stop or start transaction transmissions 704unilaterally, wherein the DUT 212 has no flow control and rather issimply notified by the agent 500 when transaction transmission 704 isincoming. As shown in FIG. 7B, like FIG. 7A, the transactiontransmission 704 comprises two datasets (data0 and data1) havingpayloads of 20:0 and 11:0. However, the transaction transmission 704 isable to comprise more or less datasets and/or transmission streams eachhaving more or less payload and/or quantity of data. In someembodiments, the driver 504 transmits the transaction transmission 704to the DUT 212 based on the outcome of the handshake protocol 702 (asexecuted by the transporter 506). Alternatively, the transporter 506 isable to retrieve the transaction from the driver 504 and transmit thetransaction transmission 704 to the DUT 212 based on the outcome of thehandshake protocol 702.

FIG. 7C illustrates a third process including a one-way handshakeprotocol with flow control 702, transaction transmission 704 andstart/end of data marking signals 706 according to some embodiments. Inparticular, the one-way handshake protocol with flow control 702comprises sending a first signal “valid” from the agent 500 to the DUT212 (via an interface). According to the handshake protocol with flowcontrol 702, the agent 500 indicates that it is ready to send data(and/or that all control and data signals are valid) when it makes“valid” high and, like the second process, the agent 500 does not waitfor, nor does the DUT 212 send, a signal that indicates that the DUT 212is ready to accept data. However, unlike the second process, the one-wayhandshake protocol with flow control 702 enables the DUT 212 to send thesignal “flow control” to indicate when the DUT 212 can no longer acceptmore data. As a result, when “valid” is high and “flow control” is low,the outcome of the protocol indicates that transaction transmission(s)704 should be transmitted and when “valid” is low or “flow control” ishigh, the outcome of the protocol indicates that transactiontransmission(s) 704 should not be transmitted or cease from beingtransmitted from the agent 500 to the DUT 212. This one-way handshakeprotocol with flow control puts control in the agent 500 over the startof transaction transmissions 704 unilaterally, but gives the DUT 212 theability to stop the transaction transmissions 704 using the flow controlsignal “flow control”. For multi-cycle transactions, in some embodimentsthe first signal portion of the third process is only performed in thefirst cycle such that subsequent cycles of the multi-cycle transactioncomprise repeating the checking for the “flow control” going high inorder to indicate that any further data is invalid. Alternatively, evenfor multi-cycle transactions the first signal portion is able to berepeated along with the “flow control” checking each cycle of thetransaction until the multi-cycle transaction is complete.

Further, as shown in FIG. 7C, the third process is able to comprisestart/end of data marking signals 706. These signals 706 are able tocomprise a start of packet (sop) signal and an end of packet (eop)signal that indicate the first data cycle and the last data cycle of thepacket (of the transaction transmission 704), respectively. As a result,the start/end of data marking signals 706 are able to be used withlarger packets and/or transaction transmissions 704 in order to indicateto the DUT 212 when each packet (or transaction 704) starts and/orstops. For example, if the agent 500 is sending data at the rate of 32bits per clock cycle, but the packets and/or chunks are greater than 32bits of data (e.g. 64 or 128 bytes/chunks), the start/end of datamarking signals 706 are able to be used to mark the end and thebeginning of the packets and/or chunks. Alternatively, the start/end ofdata marking signals 706 are able to be omitted from the third process.Additionally, it should be noted that the start/end of data markingsignals 706 are able to be added to the first, second and/or any otherhandshake processes described herein as desired to deal with longertransaction transmissions 704. Additionally, as shown in FIG. 7C, thetransaction transmission 704 comprises one dataset (data) having apayload of 31:0. However, similar to above, the transaction transmission704 is able to comprise more or less datasets and/or transmissionstreams each having more or less payload and/or quantity of data. Insome embodiments, the driver 504 transmits the transaction transmission704 to the DUT 212 based on the outcome of the handshake protocol 702(as executed by the transporter 506). Alternatively, the transporter 506is able to retrieve the transaction from the driver 504 and transmit thetransaction transmission 704 to the DUT 212 based on the outcome of thehandshake protocol 702. Additionally, although FIGS. 7A-7C illustratethe above described three handshake protocol types, it is understoodthat other types of handshake protocols are able to be used such athree-way handshakes with or without flow control or data marking andother types of handshake protocols as known in the art.

FIG. 8 illustrates an agent 800 according to some embodiments. Inparticular, the agent 800 is able to be substantially similar to theagents 206 and/or 500 except for the differences described herein.Further, although discussed separately, the agent 800 is able to replaceand/or supplement the agents in all of the embodiments described herein.As shown in FIG. 8, the agent 800 comprises a sequencer 802, a driver804, a transporter 806 and a monitor 808, wherein the sequencer 802 iscoupled with the driver 804, the transporter 806 is coupled with themonitor 808, and the monitor 808 and transporter 806 are coupled withthe DUT 212 and/or the interface 222. The transporter 806 is able to beconfigured to handle all handshaking protocol necessary forcommunicating with the DUT 212 over the interface 222 such that themonitor 808 is able to be generic in that it is not configured based onthe handshake protocol of the interface 222. In particular, by removingthe handshaking protocol responsibilities from the monitor 808 with thetransporter 806, the monitor 808 is able to be automatically generatedfor an interface 222 without any knowledge of the protocols of theinterface 222.

In some embodiments, the monitor 808 and/or transporter 806 areconfigured to monitor and/or sample all or a portion of the transactionon the interface 222 every clock cycle. In such embodiments, thetransporter 806 is able to indicate to the monitor 808 whether thesampled/monitored data or transaction is valid based on the outcome ofthe handshake protocol such that the monitor knows whether to send thesampled/monitored data to a scoreboard 210 or reference model 208 withinthe environment 204. Alternatively, the monitor 808 is able to beconfigured to only sample all or a portion of the transaction on theinterface 222 during clock cycle where the transporter 806 indicatesthat the data or transaction is valid based on the outcome of thehandshake protocol. In some embodiments the transporter 806 isconfigured to perform the handshaking protocol with the interface 222and/or DUT 212 every clock cycle. Alternatively, the performance of thehandshaking is able to be performed on a transaction basis, operationbasis, periodically, on demand, or according to other types ofschedules. In some embodiments, the monitor 808 is able to operatewithout the transporter 506 using a default handshake protocol or nohandshake protocol to determine if data is valid.

In some embodiments, the agents 500 and 800 are able to be combined suchthat the combined agent comprises both a generic driver 504 and ageneric monitor 808. In such embodiments, the driver 504 and monitor 808are able to share the same the transporter 506/806, which is coupledwith both the driver 504 and monitor 808. As a result, in suchembodiments the transporter 506/806 is able to control both the driver504 and the monitor 808 based on the outcome of the handshake protocolas described herein. Alternatively, in such embodiments the driver 504and the monitor 808 are able to have separate transporters 506/806 thatare separately coupled to the monitor 808 or the driver 504 and operateas described herein separately.

FIG. 9 illustrates a method of testing a device under test 212 within averification environment 204 of a testbench 202 according to someembodiments. Although described separately, one or more of the steps ofthe methods of FIGS. 6, 9, 12, 14 and/or 15 are able to be combined intoa single method. As shown in FIG. 9, a monitor 808 of an agent 800within the verification environment 204 monitors and/or samples one ormore transactions transmitted on an interface 222 between the agent 800and the DUT 212 at the step 902. In some embodiments, a new transactionis monitored and/or sampled each clock cycle. Alternatively, one or moreof the transactions are able to be multi-cycle such that data related toa single transaction is monitored and/or sampled over multiple cycles.The monitor 808 of the agent 800 monitors a handshake on the DUT 212according to a handshake protocol at the step 904. Specifically, thetransporter 806 and/or driver 804 of the agent 800 are able to performthe handshake with the DUT 212 (via the interface 222) according to thehandshake protocol which is monitored by the monitor 808. In otherwords, the transporter 806 is able to both drive control signals ontoand/or sample control signals from an interface 222 in order toeffectuate a handshake protocol for that interface 222 and/or DUT 212.In some embodiments, the handshake protocol used is based on interface222 and/or DUT 212. In some embodiments, the handshake protocol isindicated by the transporter class for the interface 222 within theinterface configuration file.

Based on the outcome of the handshake protocol, the monitor 808determines if the data is ready on the interface 222 and/or DUT 212 atthe step 906. The monitor 808 communicates with the transporter 806 tosample the transaction if the outcome of the handshake protocolindicates the transaction is valid at the step 908. The monitor 808forwards the sampled transaction to a scoreboard 210 or a referencemodel 208 of the verification environment 204 at the step 910. In otherwords, the transporter 806 is able to indicate to the monitor 808whether the transaction or portion of the transaction on the interface222 should be sampled and forwarded to the scoreboard 210 or referencemodel 208 because the outcome of the handshake protocol indicates thatthe transaction is valid or invalid for the cycle or cycles. In someembodiments, the communication is a control command received by themonitor 808 from the transporter 806 indicating the outcome of thehandshake protocol. In some embodiments, the monitor 808 discards orfails to forward the transaction to the scoreboard 210 or the referencemodel 208 if the outcome of the handshake protocol indicates thetransaction is invalid. As a result, the method provides the benefit ofenabling the monitor 808 to remain generic while still customizing theagent 800 for the interface 222 and/or DUT 212 by using the transporter806 to control the handshake protocol with the interface 222 and/or DUT212.

In some embodiments, the method further comprises sending data receivedfrom the DUT 212 to the one or more additional agents coupled to theagent 800 within the environment 204. In such embodiments, the handshakeprotocol used by the transporter 806 is able to be different than ahandshake protocol of a transporter of the one or more additionalagents. As described above, in some embodiments the handshake protocolis one of three handshake protocols consisting of a one-way handshakeprotocol without destination flow control, a two-way handshake protocoland a one-way handshake protocol with destination flow control.Alternatively, any number and/or combination of different or the samehandshake protocols are able to be used. In some embodiments, thehandshake protocol and/or sampling and forwarding based on the outcomeof the handshake protocol is able to be performed each clock cycle. Inaddition, if the transaction is a multi-cycle transaction, the samplingand/or forwarding is able to continue through multiple consecutive clockcycles until the multi-cycle transaction is complete (e.g. based on theend of packet or start of packet indicators). In such multi-cycleembodiments, the handshake protocol is able to still be repeated eachcycle to verify that the transaction is still valid or has becomeinvalid.

FIGS. 10A-10C illustrate three exemplary handshake protocol andtransaction transfer processes according to some embodiments. The threehandshake protocol and transaction transfer processes of FIGS. 10A-10Care substantially similar to those described in FIGS. 7A-7C except forthe differences described herein. FIG. 10A illustrates a first processof monitoring a two-way handshake protocol 1002 and transactiontransmission 1004 according to some embodiments. In particular, thetwo-way handshake protocol 1002 comprises sending a first signal “sourceready” from the driver 804 and/or transporter 806 to the DUT 212 (via aninterface) and sending a second signal “destination ready” from the DUT212 to the driver 804 and/or transporter 806. According to the handshakeprotocol 1002, the driver 804 and/or transporter 806 indicates that itis ready to send data (and/or that all control and data signals arevalid) when it makes “source ready” high and the DUT 212 indicates thatit is ready to accept data when “destination ready” is high. As aresult, when both “source ready” and “destination ready” are both high,the outcome of the protocol indicates that transaction transmission(s)1004 are valid (e.g. for sampling) and when either “source ready” or“destination ready” are low, the outcome of the protocol indicates thattransaction transmission(s) 1004 are invalid (e.g. do not need to besampled or forwarded). This two-way handshake protocol enables eitherparty (driver 804/transporter 806 or DUT 212) to stop transactiontransmissions 1004 unilaterally and restricts the beginning oftransaction transmissions 1004 to when both parties indicate that theyare ready. As shown in FIG. 10A, the transaction transmission 1004comprises two datasets (data1 and data2) having payloads of 7:0 and31:0. Alternatively, the transaction transmission 1004 is able tocomprise more or less datasets and/or transmission streams each havingmore or less payload and/or quantity of data. Based on the outcome ofthe handshake protocol 1002 (as received from the transporter 806), themonitor 808 is able to sample the datasets of the transaction 1004 forforwarding to the reference model 208 or the scoreboard 210. In otherwords, the monitor 808 is able to determine when the datasetstransmitted on the interface 222 are valid datasets (e.g. when “sourceready” and “destination ready” are high) that need to be sampled andforwarded to the desired component based on the outcome of the handshakeprotocol as indicated by the transporter 806.

FIG. 10B illustrates a second process of monitoring a simple or one-wayhandshake protocol without flow control 1002 and transactiontransmission 1004 according to some embodiments. In particular, theone-way handshake protocol without flow control 1002 comprises sending afirst signal “valid” from the driver 804 and/or transporter 806 to theDUT 212 (via an interface). According to the handshake protocol 1002,the driver 804 and/or transporter 806 indicates that it is ready to senddata when it makes “valid” high (and/or that all control and datasignals are valid), but unlike the first process, the driver 804 and/ortransporter 806 do not wait for, nor does the DUT 212 send, a signalthat indicates that the DUT 212 is ready to accept data. As a result,when “valid” is high, the outcome of the protocol indicates thattransaction transmission(s) 1004 are valid (e.g. for sampling) and when“valid” is low, the outcome of the protocol indicates that transactiontransmission(s) 1004 are invalid (e.g. do not need to be sampled orforwarded). This one-way handshake protocol puts full control in thedriver 804 and/or transporter 806 to stop or start transactiontransmissions 1004 unilaterally, wherein the DUT 212 has no flow controland rather is simply notified by the driver 804 and/or transporter 806when transaction transmission 1004 is incoming. As shown in FIG. 10B,like FIG. 10A, the transaction transmission 1004 comprises two datasets(data and data1) having payloads of 7:0 and 31:0. However, thetransaction transmission 1004 is able to comprise more or less datasetsand/or transmission streams each having more or less payload and/orquantity of data. Based on the outcome of the handshake protocol 1002(as received from the transporter 806), the monitor 808 is able tosample the datasets of the transaction 1004 for forwarding to thereference model 208 or the scoreboard 210. In other words, the monitor808 is able to determine when the datasets transmitted on the interface222 are valid datasets (e.g. when “valid” is high) that need to besampled and forwarded to the desired component based on the outcome ofthe handshake protocol as indicated by the transporter 806.

FIG. 10C illustrates a third process of monitoring a one-way handshakeprotocol with flow control 1002, transaction transmission 1004 andstart/end of data marking signals 1006 according to some embodiments. Inparticular, the one-way handshake protocol with flow control 1002comprises sending a first signal “valid” from the driver 804 and/ortransporter 806 to the DUT 212 (via an interface). According to thehandshake protocol with flow control 1002, the driver 804 and/ortransporter 806 indicates that it is ready to send data (and/or that allcontrol and data signals are valid) when it makes “valid” high and, likethe second process, the driver 804 and/or transporter 806 does not waitfor, nor does the DUT 212 send, a signal that indicates that the DUT 212is ready to accept data. However, unlike the second process, the one-wayhandshake protocol with flow control 1002 enables the DUT 212 to sendthe signal “flow control” to indicate when the DUT 212 can no longeraccept more data. As a result, when “valid” is high and “flow control”is low, the outcome of the protocol indicates that transactiontransmission(s) 1004 are valid (e.g. for sampling) and when “valid” islow or “flow control” is high, the outcome of the protocol indicatesthat transaction transmission(s) 1004 are invalid (e.g. do not need tobe sampled or forwarded). This one-way handshake protocol with flowcontrol puts control in the driver 804 and/or transporter 806 over thestart of transaction transmissions 1004 unilaterally, but gives the DUT212 the ability to stop the transaction transmissions 1004 using theflow control signal “flow control”. For multi-cycle transactions, insome embodiments the first signal portion of the third process is onlyperformed in the first cycle such that subsequent cycles of themulti-cycle transaction comprise repeating the checking for the “flowcontrol” going high in order to indicate that any further data isinvalid. Alternatively, even for multi-cycle transactions the firstsignal portion is able to be repeated along with the “flow control”checking each cycle of the transaction until the multi-cycle transactionis complete.

Further, as shown in FIG. 10C, the third process is able to comprisestart/end of data marking signals 1006. These signals 1006 are able tocomprise a start of packet (sop) signal and an end of packet (eop)signal that indicate the first data cycle and the last data cycle of thepacket (of the transaction transmission 1004), respectively. As aresult, the start/end of data marking signals 1006 are able to be usedwith larger packets and/or transaction transmissions 1004 in order toindicate to the DUT 212 when each packet (or transaction 1004) startsand/or stops. For example, if the driver 804 and/or transporter 806 issending data at the rate of 32 bits per clock cycle, but the packetsand/or chunks are greater than 32 bits of data (e.g. 64 or 128bytes/chunks), the start/end of data marking signals 1006 are able to beused to mark the end and the beginning of the packets and/or chunks.Alternatively, the start/end of data marking signals 1006 are able to beomitted from the third process. Additionally, it should be noted thatthe start/end of data marking signals 1006 are able to be added to thefirst, second and/or any other handshake processes described herein asdesired to deal with longer transaction transmissions 1004.Additionally, as shown in FIG. 10C, the transaction transmission 1004comprises one dataset (data) having a payload of 31:0. However, similarto above, the transaction transmission 1004 is able to comprise more orless datasets and/or transmission streams each having more or lesspayload and/or quantity of data.

Based on the outcome of the handshake protocol 1002 (as received fromthe transporter 806), the monitor 808 is able to sample the datasets ofthe transaction 1004 for forwarding to the reference model 208 or thescoreboard 210. Further, the monitor 808 is able to base the beginningand end of its sampling and/or forwarding on the start/end of packetsand/or transactions 1004 based on the data marking signals 1006. In someembodiments, the marking signals 1006 are directly received anddetermined by the monitor 808 from the interface 222. Alternatively, themarking signals 1006 are able to be determined based on the commandsignal from the transporter 806 and/or forwarding of the marking signals1006 from the transporter 806 to the monitor 808. In any case, themonitor 808 is able to determine when the datasets transmitted on theinterface 222 are valid datasets (e.g. when “valid” is high and/or thedata is between the sop and eop) that need to be sampled and forwardedto the desired component based on the outcome of the handshake protocolas indicated by the transporter 806. Additionally, it should be notedthat although FIGS. 10A-10C illustrate the above described threehandshake protocol types, it is understood that other types of handshakeprotocols are able to be used such a three-way handshakes with orwithout flow control or data marking and other types of handshakeprotocols as known in the art. Further, for each of the processes, thesize of the data sampled (e.g. 32 bits) is able to be determined by themonitor 808 based on the marking signals 1006, indications from thetransporter 806, a default number, or a combination thereof.

Testbench Builder Application

The testbench application is able to comprise an input module, an agentgeneration module, an interconnection module, a test case module anduser interface for interacting with the application. The input module isconfigured to input interface data (e.g. an interface file) thatdescribes the interfaces 222 associated with the DUT 212 for testing theDUT 212. For example, a single interface file is able to be input by theinput module, wherein all of the agents are able to be generated and ifnecessary customized based on the single interface file such that eachinterface associated with the DUT 212 is described in the interfacefile. In some embodiments, the interface data is able to comprise anextensible markup language (XML) file. Alternatively, the interface datais able to comprise other types of file formats. In some embodiments,the input module enables a user to manually input interface data.Alternatively or in addition, the input module is able to automaticallygenerate interface data based on an input DUT data. For example, basedon the inputs, outputs and protocols associated with the DUT 212, theinput module is able to determine a necessary number of interfaces, typeof interfaces (input, output, both), protocol and/or transaction formatassociated with each interface, and or other information about each ofthe interfaces that are necessary for testing the DUT 212. The interfacedata is able to comprise one or more of a number of needed interfaces, aname of all the ports in the interface, a width of each port (e.g.number of bits), whether each port is a control or data port, adirection of the port (e.g. input or output) with respect to the DUT212, a transaction class of each of the interfaces and/or a transporterclass of each of the interfaces. Alternatively, the interface data isable to omit the transporter class and/or transaction class of one ormore of the interfaces, which indicates that the interface has a defaulttransporter and/or transaction class.

The transaction class is able to indicate what types of data stimulus ortransactions that the interface 222 and/or DUT 212 is able tounderstand. In other words, the transaction class is a representation ofthe DUT interface in a higher level of abstraction. As a result, thesequencer 214 of the agent 206 associated with the interface 222 is ableto utilize stimulus data that is of the indicated transaction class forthe interface 222 in the interface data. The transporter class is ableto indicate what communication protocol or format (e.g. handshake) thatthe interface 222 and/or DUT 212 require for communication. For example,the transporter class is able to be one of a two-way handshake, delayedor destination flow control (DFC), one-way handshake (no flow control),or other types of communication protocol as are known in the art. Insome embodiments, the default transporter class is a two-way handshakesuch that the generic agents 206 will be automatically configured to usethe two-way handshake communication protocol. Alternatively, a differentone of the transporter classes are able to be assigned as the defaultclass that each non-customized agent utilizes. The transporter class isable to determine which of the handshake protocols that the transporter506 of an agent 500 is configured to use for the associated interface222.

The agent generation module is configured to generate each agent 206necessary for the DUT 212 based on interfaces 222 indicated in interfacedata input by the input module. Specifically, the agent generationmodule generates a generic or default agent 206 for each of theinterfaces 222 indicated in the interface data inputted by the inputmodule. These generic agents 206 are able to each comprise a driver, asequencer and a monitor that are configured to use a default protocoland default transaction class. In some embodiments, the generic driverof the agents 206 is substantially similar to the generic driver 504such that it does not handle any handshake protocol between the agent206 and the interface 222. If necessary based on the interface data, theagent generation module is then able to customize the generic agentsbased on the interface data of the interface associated with eachgeneric agent. For example, the agent generation module is able todetermine the transaction and/or transporter class for the interface 222and configure the sequencer 214 to operate based on the transactionclass and/or configure the driver 220 and monitor 216 to operate basedon the transporter class. Additionally, in some embodiments thecustomization comprises creating a transporter 506 configured to use thehandshake protocol associated with the transporter class and therebyoperate with the driver 504 as described above with reference to FIG. 5.As a result, each of the agents 206 are able to be automaticallygenerated for and customized based on each interface 222 necessary totest the DUT 212. In other words, the agents 206 that do not need to becustomized are generated and immediately ready to operate based on thedefault transaction and transporter types and the agents 206 that doneed to be modified are able to be simply reset to a non-defaulttransaction and/or transporter class and then are ready to operate withthe associated interfaces 222. For example, a non-customized agent 206is able to utilize a driver 504 that operates without or independent ofa transporter 506 and does not utilize a handshake protocol or uses adefault handshake protocol.

In some embodiments, the agent generation module is able to sort alltypes of interfaces 222 into one of the three transporter classes orhandshake protocols such that the set of transporter classes is able toonly include the three handshake protocols regardless of the number ofdifferent types of interfaces 222 required for the DUT 212. In someembodiments, the agent generation module generates the generic agents206 for all of the interfaces 222 and then customizes one or more of theagents 206 as necessary based on the associated interface 222.Alternatively, the agent generation module is able to generate a genericagent 206 and customize the generic agent 206 if necessary based on theassociated interface 222 before generating the next generic agent 206for the next interface 222. In some embodiments, the agent generationmodule instantiates the agents 206 within the environment 204 after allthe agents 206 have been generated and/or customized. Alternatively, theagent generation module instantiates each of the agents 206 within theenvironment 204 after the agent 206 has been generated and/orcustomized. In some embodiments, the agent generation module is able todynamically change the transaction and/or transporter class of one ormore agents 206 within the verification environment 204 without creatinga new testbench 202. For example, a user is able to enter commands toadd, subtract and/or modify one or more of the agents 206 using the userinterface and the agent generation module is able to implement thechanges to the agents 206 within the environment 204 automatically. As aresult, the testbench builder application provides the benefit ofautomatically creating generic and customized agents 206 for eachinterface 222 necessary to test a DUT 212.

The interconnection module is configured to generate a verificationenvironment 204 for the testbench 202. Specifically, the interconnectionmodule generates a reference model 208 and a scoreboard 210 andintegrates and instantiates the reference model 208, the scoreboard 210,the ports, the interfaces 222 and all of the agents 206 into theverification environment 204. Further, this integration is able tocomprise establishing interconnections between the reference model 208,the scoreboard 210, the agents 206, DUT 212 and the interfaces 222 viathe ports (e.g. RTL ports). In particular, the interconnection module isable to couple the ports of the DUT 212 with the interfaces 222. Forexample, if one or more of the agents 206 comprise loopback ports, theinterconnection module is able to couple one or more of the agents 206together via the loopback ports. As described above, this loopback portcoupling is able to be based on the dependency of the testing dataassociated with each of the agents 206 with respect to testing the DUT212. In particular, the interconnection module is able to automaticallycouple the loopback ports of any combination of agents 206 whose testingdata has a dependency relationship such that via the loopbackconnections all the agents 206 with the depended upon testing data sendthe associated dependency data to all the agents 206 with testing datathat is dependent on the depended upon testing data. Indeed, in someembodiments the dependent relationships of the agents 206 is able to beautomatically determined based on the interface parameters such that theloopback port coupling is able to be automatically performed by theinterconnection module based on the interface configuration file. Theinterconnection module is also able to register each of the interfaces222 in a configuration database with a unique string or other identifiersuch that each interface 222 is able to be used by one or morecomponents (e.g. agents, scoreboard, monitor) within the environment 204via a string or unique identifier based lookup in the configurationdatabase. Moreover, in some embodiments the interconnection module isable to bind the output/input of one or more of the agents 206 to one ormore other agents 206 within the environment 204.

The test case module is configured to generate one or more random orpredefined test cases for generating stimulus data for testing the DUT212 with the testbench 202. For example, the test case module is able togenerate a sample test based on the DUT 212 and/or interface data fortesting the DUT 212 once the testbench 202 has been generated. The userinterface is configured to provide users a graphical user interface forissuing commands to the testbench 202 and/or the testbench builderapplication. For example, a user is able to specify a test case based onwhich stimulus data is used to test the DUT 212, a user is able toadjust the reference module 208 operation in order to reflect changes inthe desired operation, and/or a user is able to add, subtract and/ormodify one or more of the agents 206 via the transaction and/ortransporter class values as desired. In particular, as described above,the testbench builder application is able to dynamically change thetestbench 202 and/or verification environment 204 (without creating awhole new testbench) based on such commands received from the userinterface. It should also be noted that the testbench builderapplication is also able to dynamically change the testbench 202 and/orverification environment 204 (without creating a whole new testbench)based on changed interface data received by the input module. In eithercase, the testbench builder application provides the benefit of beingable to dynamically change a testbench 202 without recreating theverification environment 204 and/or one or more of its components (e.g.agents).

FIG. 3 illustrates a method of generating a test bench according to someembodiments. As shown in FIG. 3, a testbench builder application readsan interface configuration file associated with a DUT 212 at the step302. The testbench builder application then identifies one or moreinterfaces 222 associated with the DUT 212 defined in the interfaceconfiguration file at the step 304. Based on the identified interfaces222, the application generates a verification environment 204 within thetestbench 202 including a base agent 206 for each of the interfaces 222in the interface configuration file at the step 306. In someembodiments, the generating of the verification environment furthercomprises generating one of more of the group comprising a referencemodel 208, a dispatcher 1124 and a scoreboard 210. In some embodiments,the characteristics of the base agents 206 are predefined independent ofthe interface configuration file. For example, if the base agents 206are associated with interfaces 222 that do not require anycustomization, the application is able to apply default settings to thetransporter and/or transaction class of the base agents 206 independentof the interface configuration file. These base agents 206 have defaultsettings that enable them to operate within the verification environment204 without customization.

Based on interface parameters of the interface configuration file, theapplication is able to customize one or more of the base agents 206 thatare associated with the described interface parameters at the step 308.As a result, the customized base agents 206 are able to meet thetransporter and/or transaction class needs of the interface 222 withwhich they are associated. Then the application instantiates thecustomized base agents 206 in the verification environment 204 at thestep 310. This instantiation is able to further comprise instantiationof one or more of the group comprising the base agents 206, thescoreboard 210, the reference module 208 and the dispatcher 1124, andthe coupling/binding of all of the agents 206, interfaces 222, the DUT212, the scoreboard 210, dispatcher 224 and/or the reference module 208together as desired via one or more ports. In particular, theinstantiation and/or generation of the dispatcher 224 is able tocomprise coupling all the agents 206 to one of the ports of thedispatcher 224 and generating the agent table 226 which associates theagents/interfaces/ports that are coupled to the dispatcher 224 with thescoreboard 210 or the reference model 208 as described above. Forexample, the agent table 226 is able to associate the addresses of theports that receive the data from the agents 206 with the address of theport coupled to the scoreboard 210 or the address of the port coupled tothe reference model 208. In some embodiments, the interface parametersfor each of the interfaces 222 comprise names of the ports associatedwith the interface, width of the ports associated with the interface,direction of the ports associated with the interface, and whether eachof the ports associated with the interface is for communicating controldata or non-control data. Additionally, in some embodiments the agenttable 226 is generated by the builder application based on the interfaceparameters and the binding of the ports within the verificationenvironment.

FIG. 4 illustrates a block diagram of an exemplary testbench builderdevice 102 configured to implement the testbench builder application 103according to some embodiments. The testbench builder device 102 is ableto acquire, store, compute, communicate and/or display information suchas images and videos. In general, a hardware structure suitable forimplementing the device 102 includes a network interface 402, a memory404, a processor 406, I/O device(s) 408, a bus 410 and a storage device412. Alternatively, one or more of the illustrated components are ableto be removed or substituted for other components well known in the art.The choice of processor is not critical as long as a suitable processorwith sufficient speed is chosen. The memory 404 is able to be anyconventional computer memory known in the art. The storage device 412 isable to include a hard drive, CDROM, CDRW, DVD, DVDRW, flash memory cardor any other storage device. The testbench builder device 102 is able toinclude one or more network interfaces 402. An example of a networkinterface includes a network card connected to an Ethernet or other typeof LAN. The I/O device(s) 408 are able to include one or more of thefollowing: keyboard, mouse, monitor, display, printer, modem,touchscreen, button interface and other devices. Testbench builderapplication(s) or module(s) 103 used to generate the testbench asdescribed above are able to be stored in the storage device 412 and/ormemory 404 and processed as applications are typically processed. Moreor less components shown in FIG. 4 are able to be included in testbenchbuilder device 102. In some embodiments, testbench builder hardware 420is included. Although as shown in FIG. 4 the testbench builder device102 includes applications 103 and hardware 420 for implementing thetestbench generation, it is understood that the testbench builder device102 is able to be implemented on a computing device in solely hardware,firmware or software, or any combination thereof.

In some embodiments, the testbench builder application(s) 103 includeseveral applications and/or modules. In some embodiments, the testbenchbuilder application(s) 103 include a separate module for each of thegraphical user interface features described above. The modules implementthe method described herein. In some embodiments, fewer or additionalmodules are able to be included. Examples of suitable computing devicesinclude a personal computer, a laptop computer, a computer workstation,a server, a mainframe computer, a handheld computer, a personal digitalassistant, a cellular/mobile telephone, a smart appliance, a gamingconsole, a digital camera, a digital camcorder, a camera phone, aniPod®, a video player, a DVD writer/player, a Blu-ray® writer/player, atelevision, a home entertainment system or any other suitable computingdevice.

The testbench builder system, method and device described hereinprovides numerous advantages. In particular, the builder provides theadvantage of automatically creating a fully operational testbench basedon inputted interface data. Additionally, the builder provides theadvantage of enabling the dynamic adjustment of the testbench via theuser interface or a modified interface file without having the fullyrecreate a new testbench. Moreover, the builder provides the advantageof automatically generating generic agents for interfaces that do notrequire a customized agent thereby increasing the speed of the testbenchgeneration process. Further, the testbench system provides the benefitof enabling the generic drivers to be generated independent of theinterface characteristics such as handshake protocol. Additionally, thedispatcher provides the benefit of reducing the connection complexity ofthe verification environment. In particular, the dispatcher provides asingle component that all the agents are able to be coupled andautomatically send data to instead of each agent needing a separateconnection established to either the reference model or a single line tothe scoreboard. As a result, the dispatcher is able to efficiently routethe data either on a single connection to the reference model or asingle line to the scoreboard. Moreover, the loopback ports provide theadvantage of enabling testing data dependency to be handled on an agentlevel without the use of a top level multi-layer or virtual sequencer.Also, the use of timestamps provides the advantage of enabling the eachof the agents to adjust for latency within the verification environmentwithout the use of a virtual or multilayer sequencer.

While the invention has been described with reference to numerousspecific details, one of ordinary skill in the art will recognize thatthe invention can be embodied in other specific forms without departingfrom the spirit of the invention. Thus, one of ordinary skill in the artwill understand that the invention is not to be limited by the foregoingillustrative details, but rather is to be defined by the appendedclaims.

We claim:
 1. A testbench system stored on a non-transitory computerreadable medium for testing operation of a device under test, thetestbench system comprising: a plurality of agents each comprising oneor more loopback ports within an verification environment, coupled withthe device under test and configured to perform one of outputtingtesting data to or inputting testing data from the device under testsuch that each of the agents are associated with a portion of thetesting data; wherein at least one of the portions is dependent on atleast one other of the portions with respect to testing the device undertest, and further wherein one of the loopback ports of a first agent ofthe agents that is associated with the at least one of the portions iscoupled with one of the loopback ports of a second agent of the agentsthat is associated with the at least one other of the portions fortransmitting dependency data between the one of the agents and theanother of the agents.
 2. The system of claim 1, wherein outputting thetesting data comprises outputting one or more transactions to the deviceunder test and inputting the testing data comprises inputting one ormore device responses to the transactions from the device under test. 3.The system of claim 2, wherein a second of the loopback ports of thefirst agent is coupled with a second of the loopback ports of the secondagent such that there are two connections between the first agent andthe second agent via the loopback ports.
 4. The system of claim 3,wherein the first agent is coupled with one or more additional agents ofthe agents via the loopback ports of the first agent and the additionalagents such that the first agent is coupled to a plurality of the agentsvia the loopback ports of the first agent.
 5. The system of claim 4,wherein each connection coupling two of the loopback ports has a trafficdirection configured such that an input lookout port of the ports of theagent associated with the testing data that is dependent receives thedependency data from an output lookout port of the lookout ports of theagent associated with the testing data that is depended upon.
 6. Thesystem of claim 5, wherein the dependency data is based one of the groupconsisting of the transactions and the device responses.
 7. The systemof claim 6, wherein each of the agents associated with testing data thatis dependent is configured to continuously poll an associated inputlookout port for the dependency data and each of the agents associatedwith testing data that is depended upon is configured to automaticallysend the dependency data on an associated output lookout port.
 8. Thesystem of claim 7, further comprising a dispatcher including an agenttable and coupled with a reference model and a scoreboard, wherein thedispatcher is configured to: input data comprising a copy of each of theone or more transactions and the one or more device responses to thetransactions; identify whether each portion of the data is one of thecopies of each of the one or more transactions or one of the deviceresponses based on the agent table; and route each portion of dataidentified as one of the copies of each of the one or more transactionsto the reference model and each portion of data identified as one of theone or more device responses to the scoreboard.
 9. The system of claim8, wherein each of the plurality of agents further comprise a monitorconfigured to sample the transactions and the device responses on aninterface between the agent and the device under test, to automaticallyforward the sampled transactions and device responses to the dispatcherand to send the dependency data.
 10. The system of claim 9, wherein eachof the plurality of agents further comprise a sequencer configured toreceive the dependency data and to produce one of the transactions fortesting the device under test, and further wherein each of the pluralityof agents further comprise a generic driver coupled with the sequencer,wherein the driver is configured to receive the transaction from thesequencer.
 11. The system of claim 10, wherein each of the plurality ofagents further comprise a transporter coupled with the monitor and thedriver and coupled with the device under test via the interface, whereinthe transporter is configured to perform a handshake protocol with thedevice under test over the interface based on a class of the interface.12. The system of claim 11, wherein the device under test is a virtualemulation of an electronic device.
 13. A testbench builder forgenerating a testbench for verification of a device under test, whereinthe testbench builder is stored on a non-transitory computer readablemedium and configured to perform a method comprising: reading aninterface configuration file associated with the device under test andidentifying a plurality of interfaces associated with the device undertest defined in the interface configuration file; and generating averification environment including a plurality of agents coupled withthe device under test such that there is an agent for each of theinterfaces in the interface configuration file, wherein the plurality ofagents each comprise one or more loopback ports and is configured toperform one of outputting testing data to or inputting testing data fromthe device under test such that each of the agents are associated with aportion of the testing data; wherein at least one of the portions isdependent on at least one other of the portions with respect to testingthe device under test, and further wherein one of the loopback ports ofa first agent of the agents that is associated with the at least one ofthe portions is coupled with one of the loopback ports of a second agentof the agents that is associated with the at least one other of theportions for transmitting dependency data between the one of the agentsand the another of the agents.
 14. The testbench builder of claim 13,wherein outputting the testing data comprises outputting one or moretransactions to the device under test and inputting the testing datacomprises inputting one or more device responses to the transactionsfrom the device under test.
 15. The testbench builder of claim 14,wherein a second of the loopback ports of the first agent is coupledwith a second of the loopback ports of the second agent such that thereare two connections between the first agent and the second agent via theloopback ports.
 16. The testbench builder of claim 15, wherein the firstagent is coupled with one or more additional agents of the agents viathe loopback ports of the first agent and the additional agents suchthat the first agent is coupled to a plurality of the agents via theloopback ports of the first agent.
 17. The testbench builder of claim16, wherein each connection coupling two of the loopback ports has atraffic direction configured such that an input lookout port of theports of the agent associated with the testing data that is dependentreceives the dependency data from an output lookout port of the lookoutports of the agent associated with the testing data that is dependedupon.
 18. The testbench builder of claim 17, wherein the dependency datais based one of the group consisting of the transactions and the deviceresponses.
 19. The testbench builder of claim 18, wherein each of theagents associated with testing data that is dependent is configured tocontinuously poll an associated input lookout port for the dependencydata and each of the agents associated with testing data that isdepended upon is configured to automatically send the dependency data onan associated output lookout port.
 20. The testbench builder of claim19, wherein generating the verification environment further comprisesgenerating a dispatcher including an agent table and coupled with areference model and a scoreboard, wherein the dispatcher is configuredto: input data comprising a copy of each of the one or more transactionsand the one or more device responses to the transactions; identifywhether each portion of the data is one of the copies of each of the oneor more transactions or one of the device responses based on the agenttable; and route each portion of data identified as one of the copies ofeach of the one or more transactions to the reference model and eachportion of data identified as one of the one or more device responses tothe scoreboard.
 21. The testbench builder of claim 20, wherein each ofthe plurality of agents further comprise a monitor configured to samplethe transactions and the device responses on an interface between theagent and the device under test, to automatically forward the sampledtransactions and device responses to the dispatcher and to send thedependency data.
 22. The testbench builder of claim 21, wherein each ofthe plurality of agents further comprise a sequencer configured toreceive the dependency data and to produce one of the transactions fortesting the device under test, and further wherein each of the pluralityof agents further comprise a generic driver coupled with the sequencer,wherein the driver is configured to receive the transaction from thesequencer.
 23. The testbench builder of claim 22, wherein each of theplurality of agents further comprise a transporter coupled with themonitor and the driver and coupled with the device under test via theinterface, wherein the transporter is configured to perform a handshakeprotocol with the device under test over the interface based on a classof the interface.
 24. The testbench builder of claim 23, whereingenerating the verification environment comprises generating theconnection between the loopback ports based on interface parameters ofthe interface associated with the agents as defined in the interfaceconfiguration file.
 25. The testbench builder of claim 24, wherein thedevice under test is a virtual emulation of an electronic device.
 26. Amethod of testing a device under test within a verification environmentof a testbench, the method comprising: sending dependency data from anoutput port of loopback ports of a first agent to an input port ofloopback ports of a second agent within the verification environment;continuously polling the input port of the second agent for thedependency data with a second sequencer of the second agent; producingdependent testing data for testing the device under test based on thedependency data with the second sequencer of the second agent; andreceiving the dependent testing data from the second sequencer andsending the dependent testing data to the device under test with asecond driver of the second agent.
 27. The method of claim 26, furthercomprising generating independent testing data for testing the deviceunder test with a first sequencer of the first agent and receiving theindependent testing data from the first sequencer and sending theindependent testing data to the device under test with a first driver ofthe first agent, wherein the dependency data is based on the independenttesting data.
 28. The method of claim 27, wherein the dependent testingdata is dependent upon the independent testing data with respect to thetesting of the device under test.
 29. The method of claim 26, furthercomprising inputting independent testing data for testing the deviceunder test from the device under test with a first monitor of the firstagent, wherein the dependency data is based on the independent testingdata.
 30. The method of claim 29, wherein the dependent testing data isdependent upon the independent testing data with respect to the testingof the device under test.
 31. The method of claim 30, further comprisingsending the dependency data from a second output port of the loopbackports of the first agent to an input port of loopback ports of a thirdagent within the verification environment.
 32. The method of claim 31,wherein the dependency data is sent to the second agent and the thirdagent simultaneously.
 33. The method of claim 32, further comprisingsending additional dependency data from an output port of the loopbackports of the second agent to an input port of the loopback ports of thefirst agent.
 34. The method of claim 33, wherein the device under testis a virtual emulation of an electronic device.
 35. An agent within averification environment of testbench system stored on a non-transitorycomputer readable medium for testing operation of a device under test,the agent comprising: one or more loopback ports including one or moreinput ports and one or more output ports, and configured to couple withone or more additional agents within the verification environment; amonitor coupled with the output ports and configured to input testingdata from the device under test and forward dependency data based on theinput testing data to the output ports if one or more of the outputports are coupled with at least one of the additional agents; a driverconfigured to output testing data to the device under test; and asequencer coupled with the driver and configured to receive thedependency data from the input ports if one or more of the input portsare coupled with at least one of the additional agents and to producethe output testing data for testing the device under test based on thedependency data.
 36. The agent of claim 35, wherein the loopback portsare unidirectional, the input ports are configured to receive datatraffic and the output ports are configured to output data traffic. 37.The agent of claim 36, wherein the dependency data is the input testingdata.
 38. The agent of claim 37, further comprising a transportercoupled with the monitor and the driver and coupled with the deviceunder test, wherein the transporter is configured to perform a handshakeprotocol with the device under test.